Currently, blown films are made predominantly from ethylene polymers. There are references to blowing films of propylene polymers, but none are observed to be commercially successful.
Giacobbe and Pufka in U.S. Pat. No. 5,641,848 disclose making blown films from a propylene polymer material of broad molecular weight distribution (MWD of 4-60), a melt flow rate of 0.5 to 50 dg/min. and xylene insolubles (at 25° C.) of greater than or equal to 94 percent, said propylene polymer material selected from a broad molecular weight distribution propylene homopolymer and an ethylene propylene rubber impact modified broad molecular weight homopolymer.
In some instances, blowing films of polypropylene has been achieved by coextruding a polypropylene with another polymer. For instance, Nicola disclosed in DE 19650673 the use of a rubber modified polypropylene layer between polypropylene layers. Similarly, Landoni in EP 595252 disclosed the use of linear low density polyethylene (LLDPE) or linear medium density polyethylene, optionally with added hydrogenated hydrocarbon resins or other resins or low molecular weight polyethylene or polypropylene waxes between external layers of polypropylene. In EP 474376, Schirmer et al. disclose the use of an ethylene vinyl acetate copolymer (EVA), very low density polyethylene (VLDPE) or ethylene alpha olefin copolymer with a broad molecular weight distribution with a polypropylene layer and a sealable layer.